--- /dev/null
+/*
+ * LIRC base driver
+ *
+ * by Artur Lipowski <alipowski@interia.pl>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/ioctl.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/completion.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/kthread.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+
+#include "lirc.h"
+#include "lirc_dev.h"
+
+static int debug;
+#define dprintk(fmt, args...) \
+ do { \
+ if (debug) \
+ printk(KERN_DEBUG fmt, ## args); \
+ } while (0)
+
+#define IRCTL_DEV_NAME "BaseRemoteCtl"
+#define NOPLUG -1
+#define LOGHEAD "lirc_dev (%s[%d]): "
+
+static dev_t lirc_base_dev;
+
+struct irctl {
+ struct lirc_driver d;
+ int attached;
+ int open;
+
+ struct mutex buffer_lock;
+ struct lirc_buffer *buf;
+
+ struct task_struct *task;
+ long jiffies_to_wait;
+
+ struct cdev cdev;
+};
+
+static DEFINE_MUTEX(driver_lock);
+
+static struct irctl *irctls[MAX_IRCTL_DEVICES];
+
+/* Only used for sysfs but defined to void otherwise */
+static struct class *lirc_class;
+
+/* helper function
+ * initializes the irctl structure
+ */
+static void init_irctl(struct irctl *ir)
+{
+ mutex_init(&ir->buffer_lock);
+ ir->d.minor = NOPLUG;
+}
+
+static void cleanup(struct irctl *ir)
+{
+ dprintk(LOGHEAD "cleaning up\n", ir->d.name, ir->d.minor);
+
+ device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
+
+ if (ir->buf != ir->d.rbuf) {
+ lirc_buffer_free(ir->buf);
+ kfree(ir->buf);
+ }
+ ir->buf = NULL;
+}
+
+/* helper function
+ * reads key codes from driver and puts them into buffer
+ * buffer free space is checked and locking performed
+ * returns 0 on success
+ */
+static int add_to_buf(struct irctl *ir)
+{
+ if (lirc_buffer_full(ir->buf)) {
+ dprintk(LOGHEAD "buffer overflow\n",
+ ir->d.name, ir->d.minor);
+ return -EOVERFLOW;
+ }
+
+ if (ir->d.add_to_buf) {
+ int res = -ENODATA;
+ int got_data = 0;
+
+ /* service the device as long as it is returning
+ * data and we have space
+ */
+ while (!lirc_buffer_full(ir->buf)) {
+ res = ir->d.add_to_buf(ir->d.data, ir->buf);
+ if (!res)
+ got_data++;
+ else
+ break;
+ }
+
+ if (res == -ENODEV)
+ kthread_stop(ir->task);
+
+ return got_data ? 0 : res;
+ }
+
+ return 0;
+}
+
+/* main function of the polling thread
+ */
+static int lirc_thread(void *irctl)
+{
+ struct irctl *ir = irctl;
+
+ dprintk(LOGHEAD "poll thread started\n", ir->d.name, ir->d.minor);
+
+ do {
+ if (ir->open) {
+ if (ir->jiffies_to_wait) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(ir->jiffies_to_wait);
+ }
+ if (kthread_should_stop())
+ break;
+ if (!add_to_buf(ir))
+ wake_up_interruptible(&ir->buf->wait_poll);
+ } else {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ }
+ } while (!kthread_should_stop());
+
+ dprintk(LOGHEAD "poll thread ended\n", ir->d.name, ir->d.minor);
+
+ return 0;
+}
+
+
+static struct file_operations fops = {
+ .read = lirc_dev_fop_read,
+ .write = lirc_dev_fop_write,
+ .poll = lirc_dev_fop_poll,
+ .ioctl = lirc_dev_fop_ioctl,
+ .open = lirc_dev_fop_open,
+ .release = lirc_dev_fop_close,
+ .owner = THIS_MODULE,
+};
+
+static int lirc_cdev_add(struct irctl *ir)
+{
+ int retval;
+ struct lirc_driver *d = &ir->d;
+
+ if (d->fops) {
+ cdev_init(&ir->cdev, d->fops);
+ ir->cdev.owner = d->owner;
+ } else {
+ cdev_init(&ir->cdev, &fops);
+ ir->cdev.owner = THIS_MODULE;
+ }
+ kobject_set_name(&ir->cdev.kobj, "lircv%d", d->minor);
+
+ retval = cdev_add(&ir->cdev, MKDEV(MAJOR(lirc_base_dev), d->minor), 1);
+ if (retval)
+ kobject_put(&ir->cdev.kobj);
+
+ return retval;
+}
+
+int lirc_register_driver(struct lirc_driver *d)
+{
+ struct irctl *ir;
+ int minor;
+ int bytes_in_key;
+ unsigned int chunk_size;
+ unsigned int buffer_size;
+ int err;
+
+ if (!d) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "driver pointer must be not NULL!\n");
+ err = -EBADRQC;
+ goto out;
+ }
+
+ if (MAX_IRCTL_DEVICES <= d->minor) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "\"minor\" must be between 0 and %d (%d)!\n",
+ MAX_IRCTL_DEVICES-1, d->minor);
+ err = -EBADRQC;
+ goto out;
+ }
+
+ if (1 > d->code_length || (BUFLEN * 8) < d->code_length) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "code length in bits for minor (%d) "
+ "must be less than %d!\n",
+ d->minor, BUFLEN * 8);
+ err = -EBADRQC;
+ goto out;
+ }
+
+ printk(KERN_INFO "lirc_dev: lirc_register_driver: sample_rate: %d\n",
+ d->sample_rate);
+ if (d->sample_rate) {
+ if (2 > d->sample_rate || HZ < d->sample_rate) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "sample_rate must be between 2 and %d!\n", HZ);
+ err = -EBADRQC;
+ goto out;
+ }
+ if (!d->add_to_buf) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "add_to_buf cannot be NULL when "
+ "sample_rate is set\n");
+ err = -EBADRQC;
+ goto out;
+ }
+ } else if (!(d->fops && d->fops->read) && !d->rbuf) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "fops->read and rbuf "
+ "cannot all be NULL!\n");
+ err = -EBADRQC;
+ goto out;
+ } else if (!d->rbuf) {
+ if (!(d->fops && d->fops->read && d->fops->poll)
+ || (!d->fops->ioctl)) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "neither read, poll nor ioctl can be NULL!\n");
+ err = -EBADRQC;
+ goto out;
+ }
+ }
+
+ if (d->owner == NULL) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "no module owner registered\n");
+ err = -EBADRQC;
+ goto out;
+ }
+
+ mutex_lock(&driver_lock);
+
+ minor = d->minor;
+
+ if (minor < 0) {
+ /* find first free slot for driver */
+ for (minor = 0; minor < MAX_IRCTL_DEVICES; minor++)
+ if (!irctls[minor])
+ break;
+ if (MAX_IRCTL_DEVICES == minor) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "no free slots for drivers!\n");
+ err = -ENOMEM;
+ goto out_lock;
+ }
+ } else if (irctls[minor]) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "minor (%d) just registered!\n", minor);
+ err = -EBUSY;
+ goto out_lock;
+ }
+
+ ir = kzalloc(sizeof(struct irctl), GFP_KERNEL);
+ if (!ir) {
+ err = -ENOMEM;
+ goto out_lock;
+ }
+ init_irctl(ir);
+ irctls[minor] = ir;
+
+ if (d->sample_rate) {
+ ir->jiffies_to_wait = HZ / d->sample_rate;
+ } else {
+ /* it means - wait for external event in task queue */
+ ir->jiffies_to_wait = 0;
+ }
+
+ /* some safety check 8-) */
+ d->name[sizeof(d->name)-1] = '\0';
+
+ bytes_in_key = BITS_TO_LONGS(d->code_length);
+
+ chunk_size = d->chunk_size ? d->chunk_size : bytes_in_key;
+ buffer_size = d->buffer_size ? d->buffer_size : BUFLEN / bytes_in_key;
+
+ if (d->rbuf) {
+ ir->buf = d->rbuf;
+ } else {
+ ir->buf = kmalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
+ if (!ir->buf) {
+ err = -ENOMEM;
+ goto out_lock;
+ }
+ err = lirc_buffer_init(ir->buf, chunk_size, buffer_size);
+ if (err) {
+ kfree(ir->buf);
+ goto out_lock;
+ }
+ }
+
+ if (d->features == 0)
+ d->features = (d->code_length > 8) ?
+ LIRC_CAN_REC_LIRCCODE : LIRC_CAN_REC_CODE;
+
+ ir->d = *d;
+ ir->d.minor = minor;
+
+ device_create(lirc_class, ir->d.dev,
+ MKDEV(MAJOR(lirc_base_dev), ir->d.minor), NULL,
+ "lirc%u", ir->d.minor);
+
+ if (d->sample_rate) {
+ /* try to fire up polling thread */
+ ir->task = kthread_run(lirc_thread, (void *)ir, "lirc_dev");
+ if (IS_ERR(ir->task)) {
+ printk(KERN_ERR "lirc_dev: lirc_register_driver: "
+ "cannot run poll thread for minor = %d\n",
+ d->minor);
+ err = -ECHILD;
+ goto out_sysfs;
+ }
+ }
+
+ err = lirc_cdev_add(ir);
+ if (err)
+ goto out_sysfs;
+
+ ir->attached = 1;
+ mutex_unlock(&driver_lock);
+
+ dprintk("lirc_dev: driver %s registered at minor number = %d\n",
+ ir->d.name, ir->d.minor);
+ return minor;
+
+out_sysfs:
+ device_destroy(lirc_class, MKDEV(MAJOR(lirc_base_dev), ir->d.minor));
+out_lock:
+ mutex_unlock(&driver_lock);
+out:
+ return err;
+}
+EXPORT_SYMBOL(lirc_register_driver);
+
+int lirc_unregister_driver(int minor)
+{
+ struct irctl *ir;
+
+ if (minor < 0 || minor >= MAX_IRCTL_DEVICES) {
+ printk(KERN_ERR "lirc_dev: lirc_unregister_driver: "
+ "\"minor\" must be between 0 and %d!\n",
+ MAX_IRCTL_DEVICES-1);
+ return -EBADRQC;
+ }
+
+ ir = irctls[minor];
+
+ mutex_lock(&driver_lock);
+
+ if (ir->d.minor != minor) {
+ printk(KERN_ERR "lirc_dev: lirc_unregister_driver: "
+ "minor (%d) device not registered!", minor);
+ mutex_unlock(&driver_lock);
+ return -ENOENT;
+ }
+
+ /* end up polling thread */
+ if (ir->task)
+ kthread_stop(ir->task);
+
+ dprintk("lirc_dev: driver %s unregistered from minor number = %d\n",
+ ir->d.name, ir->d.minor);
+
+ ir->attached = 0;
+ if (ir->open) {
+ dprintk(LOGHEAD "releasing opened driver\n",
+ ir->d.name, ir->d.minor);
+ wake_up_interruptible(&ir->buf->wait_poll);
+ mutex_lock(&ir->buffer_lock);
+ ir->d.set_use_dec(ir->d.data);
+ module_put(ir->d.owner);
+ mutex_unlock(&ir->buffer_lock);
+ cdev_del(&ir->cdev);
+ } else {
+ cleanup(ir);
+ cdev_del(&ir->cdev);
+ kfree(ir);
+ irctls[minor] = NULL;
+ }
+
+ mutex_unlock(&driver_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(lirc_unregister_driver);
+
+int lirc_dev_fop_open(struct inode *inode, struct file *file)
+{
+ struct irctl *ir;
+ int retval;
+
+ if (iminor(inode) >= MAX_IRCTL_DEVICES) {
+ dprintk("lirc_dev [%d]: open result = -ENODEV\n",
+ iminor(inode));
+ return -ENODEV;
+ }
+
+ if (mutex_lock_interruptible(&driver_lock))
+ return -ERESTARTSYS;
+
+ ir = irctls[iminor(inode)];
+ if (!ir) {
+ retval = -ENODEV;
+ goto error;
+ }
+
+ dprintk(LOGHEAD "open called\n", ir->d.name, ir->d.minor);
+
+ if (ir->d.minor == NOPLUG) {
+ retval = -ENODEV;
+ goto error;
+ }
+
+ if (ir->open) {
+ retval = -EBUSY;
+ goto error;
+ }
+
+ /* there is no need for locking here because ir->open is 0
+ * and lirc_thread isn't using buffer
+ * drivers which use irq's should allocate them on set_use_inc,
+ * so there should be no problem with those either.
+ */
+ lirc_buffer_clear(ir->buf);
+
+ if (ir->d.owner != NULL && try_module_get(ir->d.owner)) {
+ ++ir->open;
+ retval = ir->d.set_use_inc(ir->d.data);
+
+ if (retval) {
+ module_put(ir->d.owner);
+ --ir->open;
+ }
+ if (ir->task)
+ wake_up_process(ir->task);
+ } else {
+ if (ir->d.owner == NULL)
+ dprintk(LOGHEAD "no module owner!!!\n",
+ ir->d.name, ir->d.minor);
+
+ retval = -ENODEV;
+ }
+
+error:
+ if (ir)
+ dprintk(LOGHEAD "open result = %d\n", ir->d.name, ir->d.minor,
+ retval);
+
+ mutex_unlock(&driver_lock);
+
+ return retval;
+}
+EXPORT_SYMBOL(lirc_dev_fop_open);
+
+int lirc_dev_fop_close(struct inode *inode, struct file *file)
+{
+ struct irctl *ir = irctls[iminor(inode)];
+
+ dprintk(LOGHEAD "close called\n", ir->d.name, ir->d.minor);
+
+ WARN_ON(mutex_lock_killable(&driver_lock));
+
+ --ir->open;
+ if (ir->attached) {
+ ir->d.set_use_dec(ir->d.data);
+ module_put(ir->d.owner);
+ } else {
+ cleanup(ir);
+ irctls[ir->d.minor] = NULL;
+ kfree(ir);
+ }
+
+ mutex_unlock(&driver_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(lirc_dev_fop_close);
+
+unsigned int lirc_dev_fop_poll(struct file *file, poll_table *wait)
+{
+ struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
+ unsigned int ret;
+
+ dprintk(LOGHEAD "poll called\n", ir->d.name, ir->d.minor);
+
+ if (!ir->attached) {
+ mutex_unlock(&ir->buffer_lock);
+ return POLLERR;
+ }
+
+ poll_wait(file, &ir->buf->wait_poll, wait);
+
+ if (ir->buf)
+ if (lirc_buffer_empty(ir->buf))
+ ret = 0;
+ else
+ ret = POLLIN | POLLRDNORM;
+ else
+ ret = POLLERR;
+
+ dprintk(LOGHEAD "poll result = %d\n",
+ ir->d.name, ir->d.minor, ret);
+
+ return ret;
+}
+EXPORT_SYMBOL(lirc_dev_fop_poll);
+
+int lirc_dev_fop_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ unsigned long mode;
+ int result = 0;
+ struct irctl *ir = irctls[iminor(inode)];
+
+ dprintk(LOGHEAD "ioctl called (0x%x)\n",
+ ir->d.name, ir->d.minor, cmd);
+
+ if (ir->d.minor == NOPLUG || !ir->attached) {
+ dprintk(LOGHEAD "ioctl result = -ENODEV\n",
+ ir->d.name, ir->d.minor);
+ return -ENODEV;
+ }
+
+ switch (cmd) {
+ case LIRC_GET_FEATURES:
+ result = put_user(ir->d.features, (unsigned long *)arg);
+ break;
+ case LIRC_GET_REC_MODE:
+ if (!(ir->d.features & LIRC_CAN_REC_MASK))
+ return -ENOSYS;
+
+ result = put_user(LIRC_REC2MODE
+ (ir->d.features & LIRC_CAN_REC_MASK),
+ (unsigned long *)arg);
+ break;
+ case LIRC_SET_REC_MODE:
+ if (!(ir->d.features & LIRC_CAN_REC_MASK))
+ return -ENOSYS;
+
+ result = get_user(mode, (unsigned long *)arg);
+ if (!result && !(LIRC_MODE2REC(mode) & ir->d.features))
+ result = -EINVAL;
+ /*
+ * FIXME: We should actually set the mode somehow but
+ * for now, lirc_serial doesn't support mode changing either
+ */
+ break;
+ case LIRC_GET_LENGTH:
+ result = put_user((unsigned long)ir->d.code_length,
+ (unsigned long *)arg);
+ break;
+ default:
+ result = -EINVAL;
+ }
+
+ dprintk(LOGHEAD "ioctl result = %d\n",
+ ir->d.name, ir->d.minor, result);
+
+ return result;
+}
+EXPORT_SYMBOL(lirc_dev_fop_ioctl);
+
+ssize_t lirc_dev_fop_read(struct file *file,
+ char *buffer,
+ size_t length,
+ loff_t *ppos)
+{
+ struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
+ unsigned char buf[ir->buf->chunk_size];
+ int ret = 0, written = 0;
+ DECLARE_WAITQUEUE(wait, current);
+
+ dprintk(LOGHEAD "read called\n", ir->d.name, ir->d.minor);
+
+ if (mutex_lock_interruptible(&ir->buffer_lock))
+ return -ERESTARTSYS;
+ if (!ir->attached) {
+ mutex_unlock(&ir->buffer_lock);
+ return -ENODEV;
+ }
+
+ if (length % ir->buf->chunk_size) {
+ dprintk(LOGHEAD "read result = -EINVAL\n",
+ ir->d.name, ir->d.minor);
+ mutex_unlock(&ir->buffer_lock);
+ return -EINVAL;
+ }
+
+ /*
+ * we add ourselves to the task queue before buffer check
+ * to avoid losing scan code (in case when queue is awaken somewhere
+ * between while condition checking and scheduling)
+ */
+ add_wait_queue(&ir->buf->wait_poll, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ /*
+ * while we didn't provide 'length' bytes, device is opened in blocking
+ * mode and 'copy_to_user' is happy, wait for data.
+ */
+ while (written < length && ret == 0) {
+ if (lirc_buffer_empty(ir->buf)) {
+ /* According to the read(2) man page, 'written' can be
+ * returned as less than 'length', instead of blocking
+ * again, returning -EWOULDBLOCK, or returning
+ * -ERESTARTSYS */
+ if (written)
+ break;
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EWOULDBLOCK;
+ break;
+ }
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ mutex_unlock(&ir->buffer_lock);
+ schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (mutex_lock_interruptible(&ir->buffer_lock)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ if (!ir->attached) {
+ ret = -ENODEV;
+ break;
+ }
+ } else {
+ lirc_buffer_read(ir->buf, buf);
+ ret = copy_to_user((void *)buffer+written, buf,
+ ir->buf->chunk_size);
+ written += ir->buf->chunk_size;
+ }
+ }
+
+ remove_wait_queue(&ir->buf->wait_poll, &wait);
+ set_current_state(TASK_RUNNING);
+ mutex_unlock(&ir->buffer_lock);
+
+ dprintk(LOGHEAD "read result = %s (%d)\n",
+ ir->d.name, ir->d.minor, ret ? "-EFAULT" : "OK", ret);
+
+ return ret ? ret : written;
+}
+EXPORT_SYMBOL(lirc_dev_fop_read);
+
+void *lirc_get_pdata(struct file *file)
+{
+ void *data = NULL;
+
+ if (file && file->f_dentry && file->f_dentry->d_inode &&
+ file->f_dentry->d_inode->i_rdev) {
+ struct irctl *ir;
+ ir = irctls[iminor(file->f_dentry->d_inode)];
+ data = ir->d.data;
+ }
+
+ return data;
+}
+EXPORT_SYMBOL(lirc_get_pdata);
+
+
+ssize_t lirc_dev_fop_write(struct file *file, const char *buffer,
+ size_t length, loff_t *ppos)
+{
+ struct irctl *ir = irctls[iminor(file->f_dentry->d_inode)];
+
+ dprintk(LOGHEAD "write called\n", ir->d.name, ir->d.minor);
+
+ if (!ir->attached)
+ return -ENODEV;
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(lirc_dev_fop_write);
+
+
+static int __init lirc_dev_init(void)
+{
+ int retval;
+
+ lirc_class = class_create(THIS_MODULE, "lirc");
+ if (IS_ERR(lirc_class)) {
+ retval = PTR_ERR(lirc_class);
+ printk(KERN_ERR "lirc_dev: class_create failed\n");
+ goto error;
+ }
+
+ retval = alloc_chrdev_region(&lirc_base_dev, 0, MAX_IRCTL_DEVICES, IRCTL_DEV_NAME);
+ if (retval) {
+ class_destroy(lirc_class);
+ printk(KERN_ERR "lirc_dev: alloc_chrdev_region failed\n");
+ goto error;
+ }
+
+
+ printk(KERN_INFO "lirc_dev: IR Remote Control driver registered, "
+ "major %d \n", MAJOR(lirc_base_dev));
+
+error:
+ return retval;
+}
+
+
+
+static void __exit lirc_dev_exit(void)
+{
+ class_destroy(lirc_class);
+ dprintk("lirc_dev: module unloaded\n");
+}
+
+module_init(lirc_dev_init);
+module_exit(lirc_dev_exit);
+
+MODULE_DESCRIPTION("LIRC base driver module");
+MODULE_AUTHOR("Artur Lipowski");
+MODULE_LICENSE("GPL");
+
+module_param(debug, bool, 0644);
+MODULE_PARM_DESC(debug, "Enable debugging messages");
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